18 NORTH AMERICAN LATRACHIA AND REPTILIA. 



Order FIKMISTERNIA. 



Family ENGYSTOMID^. 

 Genus Engystoma, Fitzinger. 



Ethmoid arch ossified; prefrontals in contact with each 

 other, and with the completely ossified fronto-parietals ; terminal 

 phalanges simple ; ear fully developed ; head small, not distinct 

 from body ; tympanic membrane concealed ; toes free or slightly 

 palmate ; metatarsi with small tubercles. 



48. E. carolinense^ Holb. Head short, pointed; body 

 thick, nearly oval ; skin smooth ; toes unwebbed ; above chestnut, 

 darker along vertebral line; below grayish, thickly sprinkled 

 with black specks ; L. one inch. Austroriparian region. 



Order ARCIFERA. 



Family HYLID^. 



No postorbital process to fronto-parietals, which embrace a 

 large fontanelle; xiphisternum deeply emarginate; pupil hori- 

 zontal ; vomerine teeth present ; true pollex a simple metacarpal, 

 without phalanges. 



A. Digital dilations small. 



a. Toes broadly webbed; tongue extensively free, 

 deeply notched behind Acris. 



h. Toes free ; superior plate of ethmoid osseous ; pre- 

 frontals separate ChorophiLus. 



B. Digital dilations well developed; tongue completely 

 attached or one-third free; posterior digits webbed; vomerine 

 teeth in transverse or posteriorly convergent fasciculi Ilijla. 



Genus Acris, D. et B. 



49. A. grylhis^ subsp. gryllus, LeConte. Head elongated ; 

 snout pointed; tympanum rather indistinct; hind legs very long; 

 inner and hind part of thighs reticulated ; body above, brownish 

 or cinereous ; middle of head and back green or reddish-brown ; 

 a triangular dark patch between eyes ; a white line from orbit to 

 arm; two or three large oblique dark patches, usually margined 

 with white on sides ; these markings sometimes wanting ; beneath 

 white, often varied with dusky; chin and throat tinged with 

 yellowish; L. one and one-half inches. Austroriparian region. 



50. A. gryllus^ subsp. crepitans^ Bd. Head rather obtuse ; 

 inferior surface of thigh plain; general appearance of the pre- 



